How did human beings survive in cold temperatures without dying of strokes and heart attacks left and right when forced to eat the saturated fats found in animal foods due to the lack of available vegetation?...

that's funny stuff right there! First of all, the average age back then was like 40. Secondly, they lead an ACTIVE lifestyle. It was either that or freeze and starve to death. And thirdly, you know that they didn't die of strokes and heart attacks? I'd love to see the medical records please.